This invention relates to synchronous generators in general and more particularly to a circuit arrangement for damping power oscillations of synchronous generators in networks.
Circuit arrangements for the damping of power oscillations of synchronous generators in networks, using signals derived from power changes and sent to the exciter arrangement of at least one synchronous machine, are designed so that, for a certain limited frequency range, they form a damping signal, derived from power variations in the network which influences the voltage regulator in the sense of eliminating the effects of the power variations. When filters are used, in the chosen range, the damping signal has an optimum phase only for one oscillation frequency, so that, for a range of oscillation frequencies, as is required for operation with optimum phase over the entire range, a correspondingly large number of differently rated filters must be provided which, however, may influence each other in an undesirable manner.
It is the object of the present invention to avoid such a mutual influence of the individual filters and to prevent changes in the reactive power of the synchronous machine which are too great for a low frequency range and especially critical in view of the oscillations.